Stapling device with articulating tool assembly

ABSTRACT

A surgical stapling device includes a mounting assembly that is pivotably supported on a distal portion of a housing about a pivot axis and movable between a non-articulated position and an articulated position. A drive assembly includes a flexible body having a working end and an articulation assembly includes an active articulation link that is coupled to the mounting assembly and movable between a retracted position and an advanced position to pivot the mounting assembly about the pivot axis. A gate assembly defines a channel that receives the flexible body of the drive assembly. The active articulation link is positioned to engage the gate assembly when the active articulation link moves between its retracted and advanced positions to move the gate assembly to a position to increase the bending radius of the flexible body of the drive assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application Ser. No. 62/828,217 filed Apr. 2, 2019, the entiredisclosure of which is incorporated by reference herein.

BACKGROUND 1. Technical Description

The present disclosure is directed to surgical stapling devices, andmore particularly, to surgical stapling devices with tool assembliesthat are supported on the stapling device for articulation.

2. Background of Related Art

Surgical stapling devices configured for endoscopic or laparoscopic useinclude an elongate body having a proximal portion and a distal portion,and a tool assembly supported on the distal portion of the elongatebody. Typically, the tool assembly is supported by a pivot member thatfacilitates articulation of the tool assembly in relation to theelongate body. In some stapling devices, the tool assembly is limited toabout 45 degrees of articulation about the pivot member in one or bothdirections.

Known stapling devices include an articulation mechanism that extendsthrough a body of the stapling device and has a distal end that iscoupled to the tool assembly. Typically, the articulation mechanismincludes one or more articulation links that are movable along alongitudinal axis of the body of the stapling device to pivot the toolassembly about an axis transverse to the longitudinal axis.

In known stapling devices, the tool assembly is unstable when the toolassembly is in a non-articulated position, i.e., the position in which alongitudinal axis of the tool assembly is aligned with a longitudinalaxis the elongate body. As such, the tool assembly becomes misalignedwith the longitudinal axis of the body as the tool assembly is movedwithin a body cavity.

A continuing need exists in the art for a stapling device that includesa tool assembly that can be articulated over a wider range of angles andis stable in all positions of articulation including a non-articulatedposition.

SUMMARY

One aspect of the disclosure is directed to a surgical stapling deviceincluding a body portion, a mounting assembly, a drive assembly, anarticulation assembly, and a gate assembly. The housing includes aproximal portion and a distal portion. The mounting assembly ispivotably supported on the distal portion of the housing about a pivotaxis and movable between a non-articulated position and an articulatedposition. The drive assembly includes a flexible body having a workingend. The drive assembly is movable within the housing from a retractedposition to an advanced position. The articulation assembly includes anactive articulation link having a proximal portion and a distal portionthat is coupled to the mounting assembly. The active articulation linkis movable between a retracted position and an advanced position topivot the mounting assembly about the pivot axis. The gate assemblydefines a channel that receives the flexible body of the drive assembly,wherein the active articulation link is positioned to engage the gateassembly when the active articulation link moves between its retractedand advanced positions to move the gate assembly to a position toincrease the bending radius of the flexible body of the drive assembly.

In embodiments, the gate assembly is pivotably supported within thehousing.

In some embodiments, the gate assembly includes an upper gate and alower gate.

In certain embodiments, each of the upper and lower gates includes anelongate body and a U-shaped member supported on a distal portion,wherein the U-shaped members of the upper and lower gates define thechannel.

In embodiments, the elongate body of each of the upper and lower gatesincludes a pivot member that pivotably connects the upper and lowergates within the housing.

In some embodiments, each of the U-shaped members of the upper and lowergates includes an engagement member, wherein the active articulationlink is positioned to engage one of the engagement members of the upperor lower gates.

In certain embodiments, the articulation link includes a passivearticulation link having a distal portion coupled to the mountingassembly such that pivotal movement of the mounting assembly about thepivot axis causes movement of the passive articulation link betweenretracted and advanced positions within the housing.

In embodiments, a blowout plate is supported on each side of theelongate body of the drive assembly. Each of the blowout plates includesa distal end supported on the mounting assembly at a position distallyof the pivot axis and a proximal end supported within the housingproximally of the pivot axis.

In some embodiments, a stabilization mechanism is engaged with theactive and passive articulation links and is configured to urge themounting assembly to the non-articulated position.

In embodiments, a tool assembly is supported on the mounting assembly.

In some embodiments, the tool assembly includes a cartridge assembly andan anvil assembly.

In certain embodiments, the tool assembly is configured to receive theworking end of the device assembly.

In embodiments, the distal portion of the active articulation linkincludes a hook and the mounting assembly includes a finger, wherein thehook is positioned to engage the finger when the active articulationlink is moved towards the advanced position to assist in articulation ofthe mounting assembly.

In some embodiments, the active articulation link includes a firstactive articulation link and a second active articulation link that ispivotably coupled to the first active articulation link.

In certain embodiments, the distal portions of each of the activearticulation link and the passive articulation link include a hook andthe mounting assembly includes fingers, wherein the hooks are positionedto engage a respective one of the fingers when the respective active andpassive articulation links are moved towards the advanced position toassist in articulation of the mounting assembly.

In embodiments, the active articulation link includes a first activearticulation link and a second active articulation link that ispivotably coupled to the first active articulation link, and the passivearticulation link includes a first passive articulation link and asecond passive articulation link that is pivotably coupled to the firstpassive articulation link.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed surgical stapling deviceare described herein below with reference to the drawings, wherein:

FIG. 1 is a side perspective view of an exemplary embodiment of thepresently disclosed surgical stapling device with a tool assembly of thestapling device in a non-articulated position;

FIG. 2 is a side perspective view of the surgical stapling device shownin FIG. 1 with the tool assembly of the stapling device in anarticulated position;

FIG. 3 is an enlarged view of the indicated area of detail shown in FIG.1;

FIG. 4 is an enlarged view of the indicated area of detail shown in FIG.2;

FIG. 5 is a side perspective exploded view of a reload of the staplingdevice shown in FIG. 1 including the tool assembly;

FIG. 5A is a cross-sectional view taken along section line 5A-5A of FIG.5;

FIG. 6 is a side perspective view of articulation links of anarticulation assembly of the reload shown in FIG. 5;

FIG. 7 is a side perspective view of a proximal portion of the reloadshown in FIG. 5 with an outer tube and the anvil assembly removed andthe tool assembly in the non-articulated position;

FIG. 8 is an enlarged view of the indicated area of detail shown in FIG.7;

FIG. 9 is a side perspective view of the reload shown in FIG. 5assembled in the non-articulated position with the outer tube of thereload removed;

FIG. 10 is a side perspective view of a stabilization system of thereload assembly shown in FIG. 5;

FIG. 11 is an enlarged view of the indicated area of detail shown inFIG. 9;

FIG. 12 is an enlarged view of the indicated area of detail shown inFIG. 7;

FIG. 13 is a perspective view from the distal end of a distal portion ofa housing half-section of a proximal body portion of the reload shown inFIG. 5 with a gate assembly supported in the housing half-section;

FIG. 14 is an exploded side perspective view of the gate assembly of thereload shown in FIG. 5;

FIG. 15 is a side perspective view from the distal end of the gateassembly of the reload shown in FIG. 5;

FIG. 16 is a side perspective view from the proximal end of the gateassembly of the reload shown in FIG. 5;

FIG. 17 is a cross-sectional view taken along section line 17-17 of FIG.7;

FIG. 18 is an enlarged view of the indicated area of detail shown inFIG. 17;

FIG. 19 is a cross-sectional view taken along section line 19-19 of FIG.8;

FIG. 20 is a top view of the proximal portion of the reload shown inFIG. 6 with the outer tube and a housing half-section removed and thetool assembly in the non-articulated position;

FIG. 21 is a top view of the proximal portion of the reload shown inFIG. 6 with the outer tube and a housing half-section removed and thetool assembly in the articulated position;

FIG. 22 is a side perspective view of the proximal end of the toolassembly and the distal end of the proximal body portion with the driveassembly removed and the tool assembly in an articulated position;

FIG. 23 is a cross-sectional view through the proximal end of the toolassembly and the distal end of the proximal body portion with the driveassembly removed and the tool assembly in an articulated position; and

FIG. 24 is a top view of the proximal end of the tool assembly and thedistal end of the proximal body portion with the tool assembly in anarticulated position.

DETAILED DESCRIPTION OF EMBODIMENTS

The presently disclosed device will now be described in detail withreference to the drawings in which like reference numerals designateidentical or corresponding elements in each of the several views.However, it is to be understood that the disclosed embodiments aremerely exemplary of the disclosure and may be embodied in various forms.Well-known functions or constructions are not described in detail toavoid obscuring the present disclosure in unnecessary detail. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a basis for the claims and asa representative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure.

In this description, the term “proximal” is used generally to refer tothat portion of the device that is closer to a clinician, while the term“distal” is used generally to refer to that portion of the device thatis farther from the clinician. In addition, the term “endoscopic” isused generally used to refer to endoscopic, laparoscopic, arthroscopic,and/or any other procedure conducted through small diameter incision orcannula. Further, the term “clinician” is used generally to refer tomedical personnel including doctors, nurses, and support personnel.

Referring to FIGS. 1-4, the presently surgical stapling device is showngenerally as stapling device 10 and includes a handle assembly 12, anadapter assembly 14, and a tool assembly 16. In embodiments, the toolassembly 16 forms part of a reload assembly 18 that includes the toolassembly 16 and a body portion 20 that has a proximal portion 22 and adistal portion 24. The adapter assembly 14 and the body portion 20 ofthe reload 18 define a longitudinal axis “X” (FIG. 2). The proximalportion 22 of the body portion 20 of the reload 18 is adapted to becoupled to a distal portion 26 of the adapter assembly 14 and the distalportion of the body portion 20 is pivotally coupled to the tool assembly16 about a pivot axis “Y” (FIG. 2) that is substantially perpendicularto the longitudinal axis “X”. The tool assembly 16 is pivotal between anon-articulated position (FIG. 1) in which the tool assembly 16 isaligned with the longitudinal axis “X” and articulated positions inwhich the tool assembly 16 defines an acute angle with the longitudinalaxis “X”. It is envisioned that the tool assembly 16 may be connecteddirectly to the distal portion 26 of the adapter assembly 14 and neednot form part of a reload assembly 18.

In embodiments, the handle assembly 12 is powered and includes astationary handle 30 and actuation buttons 32 that can be actuated tocontrol various functions of the stapling device 10 includingapproximation and firing of the tool assembly 16. U.S. Pat. No.9,055,943 (“the '943 Patent”) discloses a surgical stapling devicehaving a powered handle assembly, an adapter assembly, and a toolassembly that is releasably coupled to the adapter assembly. The '943Patent is incorporated herein by reference in its entirety. Alternately,the handle assembly 12 can be manually actuated such as described inU.S. Pat. No. 5,865,361 (“the '361 Patent”) which is incorporated hereinby reference in its entirety.

Referring to FIGS. 3-5, the tool assembly 16 includes an anvil assembly40 and a cartridge assembly 42. In embodiments, the cartridge assembly42 includes a staple cartridge 42 a and channel 42 b and is pivotallycoupled to the anvil assembly 40 between an open position and a clampedposition. Alternatively, it is envisioned that the cartridge assembly 42can be stationary and the anvil assembly 40 can be movable between theopen and clamped positions such as described in the '361 Patent.

Referring to FIG. 5, the body portion 20 of the reload assembly 18(FIG. 1) includes an outer casing 44, a first housing half-section 46, asecond housing half-section 48, a mounting assembly 50, first and secondactive articulation links 52, 54, first and second passive articulationlinks 56, 58, a drive assembly 60, an articulation stabilizationmechanism 62, and a gate assembly 64. The drive assembly 60 of thereload assembly 18 includes a flexible body 68 having a working end 66.The working end 66 is movable through the tool assembly 16 to actuatethe tool assembly 16 as is known in the art. For a more detaileddescription of the structure and operation of the drive assembly 60, seethe '361 Patent. The first and second housing half-sections 46, 48,respectively, are secured together to define a housing 70 that supportsthe articulation links and the articulation stabilization mechanism 62as described in further detail below.

The mounting assembly 50 (FIG. 19) includes a first mounting portion 72,a second mounting portion 74, a first coupling member 76, and a secondcoupling member 78. The first mounting portion 72 defines a longitudinalslot 72 a and includes a pivot member 80 and internal fingers 81. Theinternal fingers 81 are positioned to engage the articulation links 52and 56 during articulation of the tool assembly 16 as discussed infurther detail below. The first coupling member 76 has a first end thatdefines an opening 76 a that receives the pivot member 80 and a secondend 76 b that is received within a recess 82 defined in a distal end ofthe first housing half-section 46 of the reload 18 such that the firstcoupling member 76 pivotably secures the tool assembly 16 to the firsthousing half-section 46. The pivot member 80 is also received in anopening 40 a (FIG. 5) defined in a proximal end of the anvil assembly 40to pivotally couple the anvil assembly 40 to the first mounting portion72 of the mounting assembly 50.

The second mounting portion 74 also includes a pivot member 84 (FIG.19). The second coupling member 48 has a first end defining an opening74 a that receives the pivot member 84 of the second mounting portion 74and a second end that is received within a recess 86 defined within thesecond housing half-section 48 to pivotally secure the second mountingportion 74 to the second housing half-section 48 of the body portion 20of the reload assembly 18. The outer casing 44 of the proximal portion22 of the reload 18 is positioned about the first and second housinghalf-sections 46, 48 to prevent separation of the first and secondhousing half-sections 46, 48 from one another and to prevent the secondends of the first and second coupling members 76, 78 from moving fromwithin the recesses 82, 86, respectively.

The second mounting portion 74 includes distal extensions 90 that definea slot 92 that is aligned with the slot 72 a in the first mountingportion 72. The distal extensions 90 are received in a proximal end ofthe anvil assembly 40 (FIG. 18) and define openings 94. The proximalends of the anvil assembly 40 and the channel 42 b of the cartridgeassembly 42 also define openings 96 that are aligned with the openings94 in the second mounting portion 74 of the mounting assembly 50. Theopenings 94 and 96 receive pivot members (not shown) to secure the anvilassembly 40 to the second mounting portion 74 and to pivotably securethe cartridge assembly 42 to the anvil assembly 40 about the pivot axis“Y” (FIG. 19).

Referring to FIGS. 3-5, the first and second mounting portions 72, 74,respectively, are secured together using pins or rivets to fixedlysecure the tool assembly 16 to the mounting assembly 50. For a moredetailed description of the interconnection between the mountingassembly 50 and the tool assembly 16, see the '361 Patent.

Referring to FIGS. 5-8, the first and second active articulation links52, 54, respectively, are supported between the first and second housinghalf-sections 46, 48 on opposite sides of the housing 70 of the bodyportion 20. The first active articulation link 52 is elongate andincludes a proximal portion 100 and a distal portion 102. The proximalportion 100 is adapted to engage an articulation drive mechanism (notshown) located within the adapter assembly 14 to translate motion of thedrive mechanism into longitudinal movement of the articulation link 52.In embodiments, the proximal portion 100 may include a transverseextension 104 that is positioned to engage the articulation drivemechanism (not shown) of the adapter assembly 14 as known in the art.Alternately, it is envisioned that the active articulation link 52 canengage the drive mechanism (not shown) of the adapter assembly 14 usinga variety of different configurations or coupling devices. The distalportion 102 of the articulation link 52 includes an inner cam surface106, a hook 108, and an opening 110. The cam surface 106 forms the innersurface of the hook 108 and is positioned to support one side of thedrive assembly 60 as described in further detail below. The cam surface106 defines a curved surface that extends towards the longitudinal axis“X” in a distal direction.

The function of the hook 108 will be described in further detail below.The opening 110 receives a pivot member 112 that is supported on thesecond active articulation link 54 to pivotally couple the second activearticulation link 54 to the distal portion 102 of the first activearticulation link 52.

The second active articulation link 54 also includes a distal portionthat defines an opening 114. The opening 114 receives a pivot member 116(FIG. 18) that is supported on a first side of the mounting assembly 50at a position transversely offset from the pivot axis “Y” (FIG. 2) topivotally secure the second active articulation link 54 to the mountingassembly 50. Although not shown, the first active articulation link 52is confined to linear movement within the housing 50 of the body portion20 of the reload assembly 18. Pivotally coupling the second articulationlink 54 between the first articulation link 52 and the mounting assembly50 increases the range of articulation of the tool assembly 16 inrelation to the adapter assembly 14 that is possible. When the firstactive articulation link 52 is moved longitudinally within the bodyportion 20 of the reload 18, the second active articulation link 54 isadvanced and pivoted about the pivot member 112 to cause pivotalmovement of the tool assembly 116 about the axis “Y” (FIG. 2). It isnoted that the length of the second active articulation link 54 issubstantially shorter than the length of the first active articulationlink 52 such that the links 52 and 54 do not protrude outwardly of themounting assembly 50 beyond a predetermined distance when the mountingassembly 50 and tool assembly 16 are articulated.

The first active articulation link 52 also defines a bushing engagementsurface 118. In embodiments, the bushing engagement surface 118 ispositioned between the proximal and distal portions 100, 102 and ispositioned to interact with the stabilization mechanism 62 (FIG. 5) toprovide stability to the tool assembly 16 in the non-articulatedposition of the tool assembly as described in detail below.

The first passive articulation link 56 includes an elongate body havinga proximal portion 120 and a distal portion 122. The proximal portion120 includes a bushing engagement surface 124 that is positioned tointeract with the stabilization mechanism 62 (FIG. 5) to providestability to the tool assembly 16 in the non-articulated position of thetool assembly 16 as described in detail below. The distal portion 122 ofthe articulation link 56 includes an inner cam surface 126, a hook 128,and an opening 130. The cam surface 126 forms the inner surface of thehook 128 and is positioned to engage one side of the drive assembly 60as described in further detail below. The cam surface 126 defines acurved surface that extends towards the longitudinal axis “X” in adistal direction. The function of the hook 128 will be described infurther detail below. The opening 130 receives a pivot member 132 thatis supported on the second passive articulation link 58 to pivotallycouple the second passive articulation link 58 to the distal portion 122of the first passive articulation link 52.

The second passive articulation link 58 also includes a distal portionthat defines an opening 134. The opening 134 receives a pivot member 136that is supported on a second side of the mounting assembly 50 topivotally secure the second passive articulation link 58 to the mountingassembly 50 at a position transversely offset from the pivot axis “Y”(FIG. 2). Although not shown, the first passive articulation link 56 isconfined to linear movement within the housing 50 of the body portion 20of the reload assembly 18. As described above in regard to second activearticulation link 54, pivotally coupling the second passive articulationlink 58 between the first passive articulation link 56 and the mountingassembly 50 increases the range of articulation of the tool assembly 16in relation to the adapter assembly 14. As discussed above in regard tothe second active articulation link 54, the length of the second passivelink 58 is substantially shorter than the length of the first passivearticulation link 56 such that the links 56 and 58 do not protrudeoutwardly of the mounting assembly 50 beyond a predetermined distance.

Referring also to FIGS. 9-12, the articulation stabilization system 62includes a biasing mechanism 140 including a slide member 142 and aplurality of springs 144. In embodiments, the slide member 142 issubstantially annular and includes a first half-section 146 and a secondhalf-section 148. The slide member 142 is slidably positioned within arecess 150 defined in an outer surface of the housing 70 of the bodyportion 20 of the reload assembly 18. The slide member 142 includesdistally extending spring mounting tabs 150, a first proximallyextending bushing 152, and a second proximally extending bushing 154. Inembodiments, each of the half-sections 146, 148 of the slide member 142includes respective side wall recesses 160 and side wall extensions 162that mesh to form the annular slide member 142.

In embodiments, the springs 144 are coil springs that have a proximalportion that is received about the spring mounting tabs 150 of the slidemember 142. Each of the springs 144 is positioned within a respectivepocket 164 defined in the housing 22 to urge the slide member 142distally about the housing 22. The first bushing 152 of the slide member142 is received within the notch 118 of the first active articulationlink 52 to urge the articulation link 52 proximally to a position inwhich the tool assembly 16 is in the non-articulated position. When thearticulation link 52 is positioned such that the tool assembly 16 is inthe non-articulated position, the springs 144 are in an unbiased statewith the bushing 152 positioned within the notch 118 and engaged withthe articulation link 52. In addition, bushing 154 is positioned withinthe surface 124 in engagement with the first passive articulation link56 to urge the articulation link 56 proximally to a position in whichthe tool assembly 16 is also in the non-articulated position. When thearticulation link 56 is positioned such that the tool assembly 16 is inthe non-articulated position, the springs 144 are in an unbiased statewith the bushing 154 engaged positioned within the surface 124 of thearticulation link 56.

For a more detailed description of the presently disclosed stabilizationsystem 62, see U.S. Patent Application No. 62/585,703 (“the '703Application”) which was filed on Nov. 14, 2017 and is incorporatedherein by reference in its entirety.

Referring also to FIGS. 13-16, the gate assembly 64 includes an uppergate 170 and a lower gate 172. Each of the upper and lower gates 170,172, respectively, includes an elongate body 174 and a U-shaped member176. When the upper and lower gates 170, 172 are assembled, the gates170, 172 define a channel 178. The channel 178 is dimensioned to receiveand allow passage of the flexible body 68 of the drive assembly 60 asthe drive assembly 60 is moved between retracted and advanced positionsto approximate and fire staples from the stapling device 10 as is knownin the art.

The elongate body 174 of each of the gates 170, 172 includes a pivotmember 180 that is pivotally coupled to an inner wall of the housing 70of the body portion 20 of the reload assembly 18 to axially fix thegates 170, 172 within the housing 70 while permitting pivotal movementof the gates 170, 172 within the housing 70. Each of the U-shapedmembers 176 of the gates 170, 172 may have an engagement member 182 thatis positioned to abut the cam surfaces 106, 126 of the articulationlinks 52, 56, respectively, as described in further detail below. Inuse, the gates 170, 172 increase a bending radius of the flexible body68 of the drive assembly 60 when the tool assembly 16 is in anarticulated position in relation to the adapter assembly 14.

Referring again to FIGS. 5 and 8, the reload assembly 18 also includesblow out plates 184. The blowout plates 184 are positioned on oppositesides of the flexible body 68 of the drive assembly 60 and extend from aposition distal of the pivot axis “Y” (FIG. 2) to a position proximal ofthe pivot axis “Y”. In embodiments, distal ends of the blow out plates184 are secured within a slot 186 (FIG. 8) in the mounting assembly 50.In some embodiments, a proximal end of the blowout plates 184 includes atransverse portion 188 that is received within a recess 190 (FIG. 8)within the housing 70 of the body portion 20 to allow the proximal endof the blow out plates 184 to slide within the housing 70. The slidingmovement allows the blowout plates 184 to adjust accordingly when theradius of curvature changes as the tool assembly 16 is articulated aboutthe pivot axis “Y”. The blowout plates 184 are positioned to obstructoutward bulging of the flexible body 68 of the drive assembly 60 duringapproximation and firing of the stapling device 10. See the '361 patentfor a more detailed description of the blowout plates 184.

Referring to FIGS. 17-20, when the tool assembly 18 of the reload 18 isin a non-articulated position, the flexible body 68 of the driveassembly 60 extends along the longitudinal axis “X” of the body portion20 of the reload 18 between the blowout plates 184 and through thechannel 178 of the gate assembly 64. In addition, the articulation links52 and 56 are urged to neutral positions by the stabilization mechanism62. In their neutral positions, the cam surface 106, 128 of thearticulation links 52, 56 are positioned in engagement with outer wallsof the blowout plates 184 and the gates assembly 64 is positioned suchthat the channel 178 defines by the gate assembly 64 is aligned with thelongitudinal axis “X”. It is noted that the engagement members 182 ofthe gates 170, 172 of the gate assembly 64 are positioned towards aproximal end of the cam surfaces 106, 126. As discussed above, the camsurfaces 106, 126 define curved surfaces that extend towards thelongitudinal axis “X” in a distal direction.

Referring to FIGS. 21-23, when the active articulation link 52 isadvanced in the direction indicated by arrows “A” in FIG. 21 byactuating the drive mechanism in the adapter assembly 14 (FIG. 1), thefirst active articulation link 52 advances the second activearticulation link 54 to pivot the mounting assembly 50 and the toolassembly 16 about the pivot axis “Y” (FIG. 19). As the tool assembly 16pivots about the pivot axis “Y”, the second passive articulation link 58is moved proximally by the pivot member 136 of the mounting assembly 50.As the second passive articulation link 58 is moved proximally, thefirst passive articulation link 56 which is pivotally coupled to thesecond passive articulation link 58 also moves proximally in thedirection indicated by arrow “B” in FIG. 21.

When the tool assembly 16 is pivoted about the pivot axis “Y”, theflexible body 68 of the drive assembly 60 bends about the pivot axis “Y”(FIG. 19). As discussed above, the gates 170, 172 (FIG. 14) of the gateassembly 64 define a channel 178 that receives the flexible body 68 ofthe drive assembly 60. When the first passive articulation link 56 isretracted in the direction indicated by arrow “B” in FIG. 21, the camsurface 126 of the first passive articulation link 56 engages theengagement surface 182 of the gate assembly 64 to pivot the gateassembly 64 about the pivot members 180 in the direction indicated byarrow “C” in FIG. 21. As the gate assembly 64 pivots about the pivotmembers 180, the gate assembly 64 engages the flexible body 68 of thedrive assembly 60 to urge the flexible body 68 towards the first activearticulation link 52. This increases the bending radius of the flexiblebody 68 of the drive assembly 60 by relocating the position of theflexible body 68 in a direction opposite to the direction ofarticulation of the tool assembly 16. As can be seen in FIG. 21, the camsurface 106 of the articulation link 52 provides added support to theouter surface of the flexible body 68 of the drive assembly 60 toprevent buckling of the flexible body 68 when the tool assembly 16 isarticulated.

As shown in FIG. 23, as the active articulation link 52 moves distallytowards the mounting assembly 50, the hook 108 on the distal portion ofthe first active articulation link 52 engages the internal finger 81 ofthe mounting assembly 50 to urge the mounting assembly 50 in thedirection of articulation.

When the first active articulation link 52 moves proximally as shown inFIG. 21, the bushing engagement surface 118 of the first activearticulation link 52 engages and urges the slide member 142 distally inthe direction indicated by arrow “K” against the urging of the springs144 to compress the springs 144. As described in detail in the '703application, the spring force of the springs 144 urges the slide member142 proximally to urge the first active articulation link 52 towards aposition in which the mounting assembly 50 is in a non-articulatedposition.

Referring to FIG. 24, when the active articulation link 52 is retractedin the direction indicated by arrows “D” by actuating the drivemechanism in the adapter assembly 14 (FIG. 1), the first activearticulation link 52 retracts the second active articulation link 54 topivot the tool assembly 16 in an opposite direction about the pivot axis“Y” (FIG. 19). As the tool assembly 16 pivots about the pivot axis “Y”(FIG. 19), the second passive articulation link 58 is moved distally andpivoted about the pivot member 136 of the mounting assembly 50. As thesecond passive articulation link 58 is moved distally, the first passivearticulation link 56 which is pivotally coupled to the second passivearticulation link 58 also moves distally in the direction indicated byarrow “E”.

When the tool assembly 16 is pivoted about the pivot axis “Y”, theflexible body 68 of the drive assembly 60 bends about the pivot axis“Y”. As discussed above, the gates 170, 172 (FIG. 14) of the gateassembly 64 define a channel 178 that receives the flexible body 68 ofthe drive assembly. When the first active articulation link 52 isretracted in the direction indicated by arrow “D” in FIG. 24, the camsurface 106 of the first active articulation link 52 engages theengagement surface 182 of the gate assembly 64 to pivot the gateassembly 64 about the pivot members 180 in the direction indicated byarrow “F”. As the gate assembly 64 pivots about the pivot members 180,the gate assembly 64 engages the flexible body 68 of the drive assembly60 to urge the flexible body 68 towards the first passive articulationlink 52. This increases the bending radius of the flexible body 68 ofthe drive assembly 60 by relocating the position of the flexible body 68in a direction opposite to the direction of articulation of the toolassembly 16. Although not shown in FIG. 24, the cam surface 126 of thefirst passive articulation link 56 supports the outer surface of theblowout plate 184 to provide added support for the flexible body 68 ofthe drive assembly 60 to prevent buckling of the flexible body 68 whenthe tool assembly 16 is articulated.

As the first passive articulation link 56 moves distally towards themounting assembly 50, the hook 128 on the distal portion of the firstpassive articulation link 56 engages the internal finger 81 of themounting assembly 50 to urge the mounting assembly 50 in the directionof articulation.

When the first passive articulation link 56 moves distally, the bushingengagement surface 124 of the first passive articulation link 52 engagesand urges the slide member 142 against the urging of the springs 144(FIG. 10) to compress the springs 144. As described in detail in the'703 application, the spring force of the springs 144 urges the slidemember 142 proximally to urge the first passive articulation link 56proximally towards a position in which the mounting assembly 50 is in anon-articulated position.

Persons skilled in the art will understand that the devices and methodsspecifically described herein and illustrated in the accompanyingdrawings are non-limiting exemplary embodiments. It is envisioned thatthe elements and features illustrated or described in connection withone exemplary embodiment may be combined with the elements and featuresof another without departing from the scope of the present disclosure.As well, one skilled in the art will appreciate further features andadvantages of the disclosure based on the above-described embodiments.Accordingly, the disclosure is not to be limited by what has beenparticularly shown and described, except as indicated by the appendedclaims.

What is claimed is:
 1. A surgical stapling device comprising: a bodyportion including a housing, a mounting assembly, a drive assembly, anarticulation assembly, and a gate assembly, the housing including aproximal portion and a distal portion, the mounting assembly beingpivotably supported on the distal portion of the housing about a pivotaxis between a non-articulated position and an articulated position, thedrive assembly including a flexible body having a working end, the driveassembly being movable within the housing from a retracted position toan advanced position, the articulation assembly including an activearticulation link having a proximal portion and a distal portion havinga cam surface, the distal portion of the active articulation link beingcoupled to the mounting assembly and movable between retracted andadvanced positions to pivot the mounting assembly about the pivot axis,the gate assembly defining a channel, the flexible body of the driveassembly extending through the channel of the gate assembly, wherein thecam surface of the active articulation link is positioned to engage thegate assembly when the active articulation link moves from its advancedposition to its retracted position to move the gate assembly to aposition to bend the flexible body of the drive assembly.
 2. Thestapling device of claim 1, wherein the gate assembly is pivotablysupported within the housing.
 3. The stapling device of claim 2, whereinthe gate assembly includes an upper gate and a lower gate.
 4. Thestapling device of claim 3, wherein each of the upper and lower gatesincludes an elongate body and a U-shaped member, wherein the U-shapedmembers of the upper and lower gates define the channel.
 5. The staplingdevice of claim 4, wherein the elongate body of each of the upper andlower gates includes a pivot member, the pivot members pivotablyconnecting the upper and lower gates within the housing.
 6. The staplingdevice of claim 5, wherein each of the U-shaped members of the upper andlower gates includes an engagement member, the active articulation linkbeing positioned to engage one of the engagement members of the upper orlower gates.
 7. The stapling device of claim 6, wherein the articulationlink includes a passive articulation link, the passive articulation linkhaving a distal portion coupled to the mounting assembly such thatpivotal movement of the mounting assembly about the pivot axis causesmovement of the passive articulation link between retracted and advancedpositions.
 8. The stapling device of claim 7, further including ablowout plate supported on each side of the elongate body of the driveassembly, each of the blowout plates having a distal end supported onthe mounting assembly at a position distally of the pivot axis and aproximal end supported within the housing proximally of the pivot axis.9. The stapling device of claim 7, further including a stabilizationmechanism, the stabilization mechanism being engaged with the active andpassive articulation links and being configured to urge the mountingassembly to the non-articulated position.
 10. The stapling device ofclaim 7, wherein the distal portion of the active articulation link andthe passive articulation link each include a hook and the mountingassembly includes fingers, the hooks being positioned to engage arespective one of the fingers when the respective active and passivearticulation links are moved towards the advanced position to assist inarticulation of the mounting assembly.
 11. The stapling device of claim7, wherein the active articulation link includes a first activearticulation link and a second active articulation link that ispivotably coupled to the first active articulation link, and the passivearticulation link includes a first passive articulation link and asecond passive articulation link that is pivotably coupled to the firstpassive articulation link.
 12. The stapling device of claim 1, furtherincluding a stabilization mechanism engaged with the articulationassembly, the stabilization mechanism being positioned to urge themounting assembly to the non-articulated position.
 13. The staplingdevice of claim 1, further including a tool assembly supported on themounting assembly.
 14. The stapling device of claim 13, wherein the toolassembly includes a cartridge assembly and an anvil assembly.
 15. Thestapling device of claim 14, wherein the tool assembly is configured toreceive the working end of the device assembly.
 16. The stapling deviceof claim 1, wherein the distal portion of the active articulation linkincludes a hook and the mounting assembly includes a finger, and thehook is positioned to engage the finger when the active articulationlink is moved towards the advanced position to assist in articulation ofthe mounting assembly.
 17. The stapling device of claim 16, wherein theactive articulation link includes a first active articulation link and asecond active articulation link that is pivotably coupled to the firstactive articulation link.